United States · 1991–2020

Best time to visit
Harrisville.

September leads for comfortable weather in Harrisville: typically 24.5°C by day, 10.1°C at night, with 105 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high24.5°C

Typical low10.1°C

Rain in September105 mm

Comfort

September

September · August · June

74climate match

Beach

July

July · August · June

59climate match

Outdoors

September

September · May · October

67climate match

The weakest month is January, scoring 5 against September’s 74 — days reach only 2.2°C, 22° below the 24°C the score treats as ideal.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

52.2° / -8.2°

Feb

53.9° / -7.6°

Mar

58.9° / -3.6°

Apr

3316.1° / 1.8°

May

6222.1° / 7.5°

Jun

6826.3° / 12.4°

Jul

6528.8° / 14.7°

Aug

6928.1° / 13.8°

Sep

7424.5° / 10.1°

Oct

4517.7° / 4.3°

Nov

1310.6° / -0.7°

Dec

54.6° / -4.8°

Monthly climate evidence for Harrisville — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	2.2°C	-8.2°C	86 mm	12.2	9 h 31	5	Strong coverage
February	3.9°C	-7.6°C	69 mm	10.4	10 h 33	5	Strong coverage
March	8.9°C	-3.6°C	90 mm	10.7	11 h 48	5	Strong coverage
April	16.1°C	1.8°C	102 mm	11.6	13 h 15	33	Strong coverage
May	22.1°C	7.5°C	107 mm	12.1	14 h 28	62	Strong coverage
June	26.3°C	12.4°C	122 mm	11.5	15 h 07	68	Strong coverage
July	28.8°C	14.7°C	119 mm	10.6	14 h 52	65	Strong coverage
August	28.1°C	13.8°C	102 mm	9.2	13 h 49	69	Strong coverage
September	24.5°C	10.1°C	105 mm	9.1	12 h 25	74	Strong coverage
October	17.7°C	4.3°C	89 mm	10.8	11 h 02	45	Strong coverage
November	10.6°C	-0.7°C	88 mm	10.5	9 h 49	13	Strong coverage
December	4.6°C	-4.8°C	80 mm	11.4	9 h 13	5	Strong coverage

What has changed

Harrisville runs +1.1°C
on the 1961–1990 baseline.

Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.

Jan

+1.1

Feb

+1.9

Mar

+1.1

Apr

+0.7

May

+1.2

Jun

+0.4

Jul

+1.3

Aug

+1.0

Sep

+1.5

Oct

+0.9

Nov

+0.2

Dec

+2.2

September daytime highs, 2011–2025. Last recorded: 25.1°C.

Records at SLIPPERY ROCK 1 SSW, 1949–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.2°C26 Jan 1950	-33.3°C19 Jan 1994	42 mm24 Jan 2010	184 mm2005 · driest 23 mm in 1967	76
February	23.3°C25 Feb 2017	-29.4°C11 Feb 1979	39 mm25 Feb 2022	155 mm2018 · driest 11 mm in 1987	77
March	30.6°C24 Mar 2012	-23.3°C15 Mar 1993	65 mm28 Mar 1985	167 mm1985 · driest 21 mm in 1958	77
April	31.7°C27 Apr 2009	-12.8°C1 Apr 1987	51 mm25 Apr 1993	230 mm2024 · driest 22 mm in 1960	77
May	35.6°C11 May 2015	-5.6°C9 May 1983	51 mm22 May 2025	192 mm1953 · driest 30 mm in 1977	78
June	37.2°C17 Jun 1952	-1.1°C11 Jun 1980	71 mm15 Jun 2015	281 mm1956 · driest 31 mm in 1967	78
July	38.9°C23 Jul 2011	2.8°C6 Jul 1979	100 mm6 Jul 2026	251 mm1992 · driest 29 mm in 1997	78
August	37.2°C30 Aug 1953	-2.2°C28 Aug 1982	88 mm15 Aug 1980	223 mm1980 · driest 14 mm in 1953	75
September	37.2°C2 Sep 1953	-2.8°C20 Sep 1979	120 mm8 Sep 2004	212 mm2004 · driest 13 mm in 1959	76
October	32.8°C7 Oct 2007	-11.1°C31 Oct 1975	98 mm16 Oct 1954	229 mm1954 · driest 8 mm in 1963	76
November	27.2°C3 Nov 1961	-18.3°C30 Nov 1958	78 mm30 Nov 2010	305 mm1985 · driest 25 mm in 2009	76
December	23.3°C3 Dec 1982	-28.9°C24 Dec 1989	58 mm2 Dec 1991	150 mm2007 · driest 12 mm in 1955	76

Typical days per month at SLIPPERY ROCK 1 SSW, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	27	3	10
February	0	0	24	2	7
March	<1	0	23	3	4
April	3	<1	12	4	1
May	11	2	3	4	0
June	20	7	0	4	0
July	27	12	0	4	0
August	25	10	0	3	0
September	15	4	<1	3	0
October	4	<1	7	3	<1
November	<1	0	18	3	2
December	0	0	25	3	6

How often, not how much — every day in SLIPPERY ROCK 1 SSW’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	<1%	37%	7%	51%	-1.9–5.2°C
February	<1%	34%	7%	46%	0.1–6.6°C
March	6%	36%	9%	52%	5.4–12.1°C
April	20%	38%	11%	51%	12.7–18.3°C
May	42%	37%	12%	51%	18.8–24.7°C
June	61%	35%	14%	45%	24.1–27.8°C
July	67%	32%	13%	39%	26.3–30.6°C
August	70%	29%	10%	33%	25.5–29.4°C
September	60%	29%	10%	36%	21.6–25.9°C
October	29%	31%	8%	38%	15.3–19.8°C
November	5%	35%	9%	48%	7.4–13.0°C
December	<1%	37%	7%	51%	0.4–7.2°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1951Each stripe is one year’s mean temperature against the 71-year average. Warmest: 2012. Coolest: 1978.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5192756
NOAA station: USC00368184 · SLIPPERY ROCK 1 SSW
Station distance: 9.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 41.14°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from SLIPPERY ROCK 1 SSW is what differs

Grove City→Slippery Rock→Lake Arthur Estates→Bruin→Clintonville→West Liberty→

Or put two places side by side: Harrisville vs Grove City

Best time to visitHarrisville.

September

July

September

The whole year,without the guesswork.

Harrisville runs +1.1°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Harrisville.

The whole year,
without the guesswork.

Harrisville runs +1.1°C
on the 1961–1990 baseline.

Nearby, measured,
and named.